Separate keyboard scancodes for "Pause" and "Break"

SDL currently has two separate key codes for "Print Screen" and "System Request" (see also #16252). Its close neighbour Pause/Break, however, does not get this treatment.

In Linux, Pause is assigned to evdev ID 148 (https://github.com/libsdl-org/SDL/blob/dc05826028d6850ccc48661010ac444942cec0af/src/events/scancodes_linux.h#L148), whereas Break can be found later at line 411 (https://github.com/libsdl-org/SDL/blob/dc05826028d6850ccc48661010ac444942cec0af/src/events/scancodes_linux.h#L441).

In Windows, according to the following Microsoft document: https://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/translate.pdf

• Break is represented by E0 46, which is currently assigned to Pause: https://github.com/libsdl-org/SDL/blob/dc05826028d6850ccc48661010ac444942cec0af/src/events/scancodes_windows.h#L227
• Pause is represented by E1 1D 45, which doesn't appear on the Windows document at all

Microsoft virtual keys map Pause to 0x13 and Break to 0x03 (https://learn.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes), however I'm not sure if SDL can even take advantage of these.